Khan Academy Critical Thinking Instant Message Research Papers
Now this is a special, technical use of[br]the word "valid." In ordinary life, we often use this word[br]to mean something like good, cogent, or reasonable.Like if you're disagreeing with someone[br]about something, and they respond to a claim you make by saying something that[br]seems pretty reasonable to you, you might say, "Well, I guess you have[br]a valid point." Though that's what the word often means[br]in ordinary life, it's not what the word means here."Merely taking the test isn't sufficient [br]for passing it." "The lawyer convinced the jury that there is sufficient evidence to [br]convict the accused." "Pain is a necessary part of every human[br]life." "Practice is really necessary for [br]success." But what exactly do these words mean?If P is necessary for Q, then Q cannot be[br]true unless P is true.But not all deductive arguments are good,[br]and so there are several things to think about when deciding whether to believe the[br]conclusion of a deductive argument.A good deductive argument really does[br]guarantee its conclusion.If you're behind a web filter, please make sure that the domains *.and *.are unblocked. I'm Jeff Pynn, and I teach philosophy[br]at Northern Illinois University.
Steering well is a necessary condition[br]for driving well.
Seems like that is pretty sufficient for [br]getting accepted to university.
Now, necessary and sufficient conditions [br]come in all combinations.
Boiling potatoes in water is a sufficient[br]condition for cooking them, since it's true that boiling potatoes is [br]enough to cook them.
However, boiling potatoes in water is not [br]a necessary condition for cooking them, since you can cook them in many other [br]ways: frying them, grilling them, baking them, [br]roasting them.